Bestie I was having APFT thoughts for you
Maybe Jesper is like jealous of Matthias for a little while because he and Wylan are so close Jesper starts to think they're together. Also, personal HC for Wylan Matthias friendship, Wylan steals Matthias' clothes like a maniac and they're so oversized on him, but I digress. So because of these things Jesper thinks they're dating and that's why Matthias gets so mad at him for flirting with Wylan when it's actually just big bro energy.
Also because Wylan can be dense:
Jesper: So... how long have you and Matthias been together?
Wylan, oblivious: Oh, a few years now.
Jesper: Oh, wow. That's a long time.
And then later Wylan is like "WAIT A FUCKING MINUTE" and clears everything up
I think this would be both angsty, funny, and demonstrate Matthias and Wylan's friendship quite well BIT OBVIOUSLY IT'S JUST SOME INSPO FOR YOU 🤗 I'M SO EXCITED 🩷✨
This has cured me of all ailments, it's exactly what I needed. I am a dying Victorian child, begging for a scrap of bread to last me throughout the winter. And you've given me a whole damn BUFFET
Matthias knows what Jesper thinks but he finds it so damn funny how dense Wylan is
Jesper, nearly bursting with jealousy: So, uh, Matthias and you, yeah?
Jesper: How long've you two been,,, yknow
Wylan: Mhm. We only really had each other and travelling all that time...
Jesper: Makes you think, doesn't it?
Jesper: So you, uh, you love him, then?
Wylan: Matt? Course I love him, he's like a brother to me